TSI Supercool Radiator UV Leak Detection Dye — Purple 8 oz Self-Measure Bottle, Water-Based

TSI Supercool RD8 is an 8-ounce, water-based purple UV-detectable radiator dye in a self-measuring bottle designed to locate cooling system leaks quickly and precisely.

If you suspect a coolant leak but can't see obvious drips or stains, adding a UV-reactive dye to the radiator or coolant reservoir makes small leaks visible under a UV lamp. The RD8 formula is synthetic, water-compatible, and engineered to show up under any U/V light so you can trace the source without disassembling large sections of the engine. Its self-measure bottle lets you dispense the recommended 1 ounce per vehicle without extra tools, saving time in garages, home workshops, or roadside troubleshooting.

How does the dye reveal hidden cooling system leaks?

When added to the coolant, the RD8 dye circulates with the system fluid. Any escaping fluid deposits the purple dye at the leak point, which fluoresces brightly under a UV lamp and pinpoints hairline cracks, gasket failures, or loose hose clamps. This visual cue reduces guesswork and helps you find leaks faster than pressure testing alone.

• Mixes with water-cooled systems and travels with coolant flow
• Fluoresces under standard U/V lights for easy detection
• Highlights small leaks invisible to the naked eye
• Works on hoses, radiators, gaskets and fittings

How much dye do I need and how do I use it safely?

RD8 is packaged in a user-friendly self-measure bottle and the typical dose is 1 ounce per vehicle, which is enough for most passenger cars and light trucks. Add the dye to the coolant reservoir or radiator when the engine is cool, circulate the system briefly, then inspect with a UV lamp. Follow all safety precautions for working with hot engines and coolant; avoid direct skin or eye contact and properly dispose of any waste coolant.

• Dosage: 1 ounce per vehicle (8-ounce bottle covers multiple uses)
• Application: add to coolant reservoir or radiator when cool
• Inspection: run engine briefly, then scan with U/V light
• Safety: avoid skin/eye contact; follow coolant handling guidelines

Is this dye compatible with my cooling system and detection tools?

RD8 is water-based and formulated for use in water-cooled engines; it’s designed to be compatible with common cooling system materials. The dye is detectable with any standard U/V lamp, so it works with professional leak-finding lights or handheld UV flashlights used by DIYers. As with any additive, check vehicle manufacturer guidance if a specific coolant chemistry is required.

• Water-based formula for water-cooled systems
• Detectable with standard U/V lights and flashlights
• Suitable for radiators, hoses, heater cores and fittings
• Consult manufacturer requirements for specialized coolants

How quickly will I find a leak after adding the dye?

Many leaks become visible within minutes of circulating the system, but some slow or intermittent leaks may take longer or require short road tests. After adding RD8 and running the engine, inspect likely leak points under a UV lamp; repeat checks after a brief drive for systems where leaks appear only under pressure or temperature cycles.

• Quick leaks often show within minutes of circulation
• Slow or pressure-dependent leaks may need a short drive
• Inspect radiator, hoses, clamps, gaskets and heater core areas
• Recheck after cooling to catch residual traces

Who is this for: TSI Supercool RD8 is intended for mechanics, fleet technicians, and vehicle owners who need a straightforward, reliable way to detect coolant leaks without invasive disassembly. The self-measure bottle and one-ounce dosing make it convenient for shop use and home mechanics alike, while compatibility with standard UV lights ensures quick, accurate leak location across a wide range of water-cooled vehicles.